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CHARLES H. L'AVIS, 0E PHILADELPHIA, PENNSYLVANIA, .ASSIGNoE rTo,

PHILIP FARLEY, y OF ASAME PLACE.-

Lenefspqentlvo. 74,385, and Eebraary 11,1868. S

IMPEovED TUBE-sometimes.'

To ALL wHoM Ir MAY oNcERNY:

I Be it known that I, CHARLES IH. LAYIS, ofthe city and county of Philadelphia, and State of Pennsylvania, have in vented a new and improved Boring-Bar or- Tube-Sheet Bor'er; and Ido hereby declare that the following` is a full, clear, and exact descrptionofthe same, reference being had'to the accompanying drawing, and `to the letters of reference marked thereon, making part ofthis specification, in whichw i i Figure 1 is an elevation,

Figure 2 is a sectional elevation, Figure Sis an end view of the, shank, and Figure 4 shows a sheet partly grooved or cut.

Similar letters refer to similar parts in -the several views. i

A is a shank, which is forged with a swell orl large portion, B, on its end. It has longitudinal grooves, a a a as s ho'wn in iig. ,3, formed in'its outer surface, corresponding tothe number of outters,`b b b, which take into these grooves. Any number of cutters can be employed, four being shown in this instance, their cutting parts, being curved to suit the circle they work in. A ring, C, is-slipped over'the 'cutters to hold them firmly inplace, and adjust them 'sc that allthe points may work at once. This ring has set-screws, d d d, foreach. cutter, and one of the cutters maybe `made tocountersink or give a bevel to the hole or Hue-opening at the same time that 4it is bored, or an'additionalcntter, solely for the4 purpose of oountersinking, may be employed. A socket, e, is formed in the shank A, commencing at its lower or enlarged end. A centre, D,^takes'nto it. `A spiral or, other spring, E, is also inserted into the-said opening or socket, above the centre D, its ends bearing against the top of the centre and 4the top of the socket. f is a slot, formed either through 'or partly through the shank screw or pin, g, which keeps the centre D from either dropping orbeing forced out of" the socket by the spring F, by being fixed to the said centre, moves up and down in the said siot with Athe centre,

and is so adjusted .relative to it, that when vthe centre is at its lowestpoint,l the pin is locked or held in the" `bottom end of the slot. i

To operate my boring-bar or tube`hole cutter for boilers,.&e., thesheet to be bored having been previously markedo' and centre punehed, is placed on the. table 'of a'drillpress, and the shank, A, inserted into the spindle ofthe same, which is then screwed down until the point of the centre D takes into either of thecentre punch-marks. On the press being started and the spindle fed down, ther cutters b feed into the sheet, and remove a ring-ofmetal corresponding tothe width'ot' the cutters. It will b e observedthat as the cutters feed down, the centre, D, moves up the socket e in the shank, compressing the-spring E, and` when the cutters have performed their work, the spring reacts and forces the 'centre down, thereby removing the washer or circular ilat plate of metal remaining. A

1,* The advantages of this tool for cutting out the'tube-holes inv the flue-sheets of boilers are, that 1t works fast and with great certainty of execution, and thezeutters, whith often break even` with the'greatest care, can

be easily dressed when broken, in a short time, and at aslightcost, thus making its useeconomical both -in point of execution andeost of repair.

Whatl I claim as my invention, and desire to secure by Letters Patent, i-s- A i The tool, as awhole, when its several parts are combined, constructed, and arranged as set forth; In testimony whereof, I hereunto sign mynaixxe to this-specification, in presence of 'two subscribing witnesses.

' CHARLES H. LAvIS. Witnesses: A

i J. P. DELANEY', l PHILIP J. TAYLOR. 

